Computer system for supplying electric power to external apparatus and control method thereof

ABSTRACT

A computer system includes multiple ports to which at least one external device is connected and which are connectable to multiple power supplying lines branched from a power supplying line for supplying electric power to the at least one external device; a switching unit which controls connections between the power supplying lines and the ports; and a controller which controls the switching unit so that two or more power supplying lines among the power supplying lines are connected to a first port, to which one of the at least one external device is connected, among the ports.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.2008-38409, filed on Apr. 24, 2008 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the present invention relate to a computer system and acontrol method thereof, and more particularly, to a computer system witha plurality of ports to which external devices are mounted and fromwhich the external devices can draw electric power, and a control methodthereof.

2. Description of the Related Art

A computer system (such as a desktop computer, a laptop computer, or thelike) includes various ports for interfaces with internal or externaldevices. As a representative example of the ports, there is a universalserial bus (USB) port. FIG. 1 is a block diagram of a conventionalcomputer system 10 with a USB port. The computer system 10 includes acentral processing unit 11, an input/output control hub (ICH) 13 forinput/output control of peripheral units, and a memory control hub (MCH)12 for memory control. Further, the computer system 10 includes aplurality of USB ports 14 and 15, to which a corresponding externaldevice 21 is mounted according to a USB standard.

Each of the USB ports 14 and 15 is connected to a power source Vcc of 5Vso that the external device 21 can draw electric power therefrom.Specifically, as shown in FIG. 1, power terminals PWR1 and PWR2 of theUSB ports 14 and 15 are connected to power supplying lines 17 and 18branched from the power source Vcc, respectively. The computer system 10includes a power switch 16 to cut off an overcurrent when theovercurrent flows in the power supplying lines 17 and 18, therebypreventing element damage, fire, etc.

Meanwhile, the USB specification, such as USB Specification 2.0,describes that the USB ports 14 and 15 each is provided with a directcurrent (DC) power of 5V and a current of 500 mA. Thus, the computersystem 10 has a power configuration designed in consideration of thisspecification.

However, an external device 21 that needs an electric power of 500 mA ormore has recently come out as the performance thereof is enhanced or forthe like reasons. In this case, if the power supplying lines 17 and 18are not designed to supply the electric power proper for the externaldevice 21, the external device 21 may abnormally operate due to supplyof insufficient electric power.

To solve this problem, there have been considered methods in whichintensity of suppliable current increased per power supplying line, anadditional power source is connected to the port, etc. However, thesemethods increase the costs of the power configuration. Further, if theconnection of the additional power source depends on manipulation of auser, it brings inconvenience to a user. Also, a user may not make gooduse of the additional power source for lack of adequate understanding.

SUMMARY OF THE INVENTION

It is an aspect of the present invention to provide a computer systemcapable of supplying sufficient electric power to an external apparatusmounted to a port thereof with low costs, and a control method of thesame.

Another aspect of the present invention is to provide a computer systemcapable of supplying sufficient electric power to an external apparatusmounted to a port thereof with high reliability and convenience, and acontrol method of the same.

An aspect of the present invention can be achieved by providing acomputer system including: a plurality of ports to which at least oneexternal device is mounted and which is connectable to a plurality ofpower supplying lines branched from a power supplying line for supplyingelectric power to the at least one external device; a switching unitwhich controls connections between the plurality of power supplyinglines and the plurality of ports; and a controller which controls theswitching unit so that two or more power supplying lines among theplurality of power supplying lines are connected to a first port, towhich one of the at least one external device is being mounted, amongthe plurality of ports.

According to an aspect of the present invention, the controller maydetermine whether the at least one external device is lacking inelectric power on the basis of registered information about the at leastone external device, managed by an operating system of the computersystem.

According to an aspect of the present invention, the controller mayselect a power supplying line connected to a second port, to which theat least one external device is not being mounted, among the pluralityof power supplying lines, as at least one of the two or more powersupplying lines to be connected to the first port.

According to an aspect of the present invention, the controller maycontrol the switching unit so that the two or more power supplying linesare additionally connected to the first port at least one by one.

According to an aspect of the present invention, the controller may givea user a message of asking him/her to remove the at least one externaldevice being mounted to other ports among the plurality of ports thanthe first port.

According to an aspect of the present invention, the controller maydisconnect at least one of the two or more power supplying lines and thefirst port if the at least one external device is removed from the firstport.

According to an aspect of the present invention, the switching unit mayinclude: a plurality of switching elements which controls connectionsbetween the plurality of second power supplying lines and the pluralityof ports; and a switching driver which may drive the plurality ofswitching elements on the basis of a control signal.

According to an aspect of the present invention, the controller mayinclude: an input/output controller which outputs the control signal tothe switching driver; and a program executer which executes a computerprogram so that the input/output controller outputs the control signal.

According to an aspect of the present invention, the foregoing and/orother aspects of the present invention can be achieved by providing amethod of controlling a computer system, including: selecting a firstport among a plurality of ports to which at least one external device ismounted and which is connectable to a plurality of power supplying linesbranched from a power supplying line for supplying electric power to theat least one external device; and connecting two or more power supplyinglines among the plurality of power supplying lines to the first port, towhich one of the at least one external device is being mounted.

According to an aspect of the present invention, the selecting of thefirst port includes determining whether the at least one external deviceis lacking in electric power on the basis of registered informationabout the external device, managed by an operating system of thecomputer system.

According to an aspect of the present invention, the method furtherincludes selecting a power supplying line connected to a second port, towhich the at least one external device is not being mounted, among theplurality of power supplying lines, as at least one of the two or morepower supplying lines to be connected to the first port.

According to an aspect of the present invention, the connecting of thetwo or more power supplying lines may include additionally connectingthe two or more power supplying lines to the first port at least one byone.

According to an aspect of the present invention, the method furtherincludes giving a user a message of asking him/her to remove the atleast one external device being mounted to other ports among theplurality of ports than the first port.

According to an aspect of the present invention, the method furtherincludes disconnecting at least one of the two or more power supplyinglines and the first port if the at least one external device is removedfrom the first port.

An aspect of the present invention can be achieved by providing acomputer system including: a plurality of ports to which at least oneexternal device is mounted and which is connectable to a plurality ofpower sources for supplying electric power to the at least one externaldevice; a switching unit which controls connections between theplurality of power sources and the plurality of ports; and a controllerwhich controls the switching unit so that two or more power sourcesamong the plurality of power source are connected to the port, to whichone of the at least one external device is being mounted, among theplurality of ports if the at least one external device being mounted toone of the plurality of ports is lacking in the electric power.

According to an aspect of the present invention, the controller maydetermine whether the at least one external device is lacking inelectric power on the basis of registered information about the at leastone external device, managed by an operating system of the computersystem.

An aspect of the present invention can be achieved by providing a methodof controlling a computer system, including: selecting a first portamong a plurality of ports to which at least one external device ismounted and which is connectable to a plurality of power sources forsupplying electric power to the at least one external device; andconnecting two or more power sources among the plurality of powersources to the first port, to which one of the at least one externaldevice is being mounted, among the plurality of ports.

According to an aspect of the present invention, the selecting of thefirst port may include determining whether the at least one externaldevice is lacking in electric power on the basis of registeredinformation about the at least one external device, managed by anoperating system of the computer system.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a block diagram of a conventional computer system with auniversal serial bus (USB) port;

FIG. 2 is a block diagram of a computer system according to anembodiment of the present invention;

FIG. 3 illustrates operations of a switching unit according to anembodiment of the present invention;

FIG. 4 illustrates an example of a configuration of the switching unitof FIGS. 2 and 3; and

FIG. 5 is a flowchart for operations of a controller shown in FIG. 2according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures. The present invention maybe embodied in various forms without being limited to the embodimentsset forth herein. Descriptions of well-known parts are omitted forclarity, and like reference numerals refer to like elements throughout.

FIG. 2 is a block diagram of a computer system 100 according to anembodiment of the present invention. The computer system 100 may berealized as a desktop computer, a laptop computer, a portable mediaplayer, a personal digital assistant, a smart phone, or other likedevice connectable to peripheral units. The computer system 100 includesa central processing unit 101, an input/output control hub (ICH) 103 forinput/output control of peripheral units, and a memory control hub (MCH)102 for memory control.

For interfaces with corresponding external devices 201, 202 and 203, thecomputer system 100 includes a plurality of universal serial bus (USB)ports 104, 105 and 110 to which the external devices 201, 202 and 203may be mounted. In this embodiment, only three ports, e.g., a first USBport 104, a second USB port 105 and a third USB port 110 are shown forconvenience, but the invention is not limited thereto. Alternatively,more or less than three ports may be provided in the computer system100, and additional non-USB ports can be used in addition to the shownports, including ports which do not requires power supplied from thecomputer system 100.

Hereinafter, if not mentioned specifically, the “USB ports 104, 105 and110” indicate all or some USB ports not shown but providable, whichinclude the first USB port 104, the second USB port 105 and the thirdUSB port 110. Likewise, if not mentioned specifically, the “externaldevices 201, 202 and 203” indicates all or some external devices notshown but providable, which include a first external device 201, asecond external device 202 and a third external device 203. As such, theinvention is not limited to the shown number of devices and ports, whichcan be more than or fewer than the shown those depicted in the exampledescribed herein. While not limited thereto, in the shown example, theexternal device 201 corresponds to the USB port 104, the external device202 corresponds to the USB port 105, and the external device 203corresponds to the USB port 110. However, only the external device 201is connected to the USB port 104, whereas the external devices 202,203have not been connected to the USB ports 105,110.

Each of the USB ports 104, 105 and 110 are connected to a power sourceVcc in order to supply electric power to the external devices 201, 202and 203. In detail, as shown in FIG. 2, first power supplying lines 107,108 and 109 branch from the power source Vcc and are connected to secondpower supplying lines 112, 113 and 114, respectively. The second powersupplying lines 112, 113 and 114 are connected to the correspondingpower terminals PWR1, PWR2 and PWR3 of the USB ports 104, 105 and 110.While not limited thereto, in the shown example, the second powersupplying line 112 is connected to the corresponding power terminal PWR1of the USB port 104, the second power supplying lines 113 is connectedto the corresponding power terminal PWR2 of the USB port 105, and thesecond power supplying line 114 is connected to the corresponding powerterminal PWR3 of the USB port 110.

For convenience, the first power supplying lines 107,108 and 109 and thesecond power supplying lines 112, 113 and 114 are illustrated onlycorresponding to the USB ports 104,105 and 110. The computer system 100may be provided with the first power supplying lines and the secondpower supplying lines corresponding to the not-shown USB ports or nonUSB ports requiring power. Similarly, if not mentioned specifically, the“first power supplying lines 107, 108 and 109” and the “second powersupplying lines 112, 113 and 114” may indicate all or some powersupplying lines not shown as well as the shown lines 107, 108, 109, 112,113, 114.

Further, the shown computer system 100 includes a power switch 106 tocut off an overcurrent when the overcurrent flows in the first powersupplying lines 107, 108 and 109, thereby preventing element damage,fire, etc. However, it is understood that the power switch 106 is notrequired in all aspects.

The computer system 100 additionally includes a switching unit 111 toselectively connect the first power supplying lines 107, 108 and 109with the second power supplying lines 112, 113 and 114. The switchingunit 111 selectively connects the first power supplying lines 107, 108and 109 with the second power supplying lines 112, 113 and 114 on thebasis of an input control signal.

FIG. 3 illustrates operations of the switching unit 111 according to anembodiment of the present invention. The switching unit 111 connects atleast one of the first power supplying lines 107, 108 and 109 with oneof the second power supplying lines 112, 113 and 114 on the basis of aninput control signal. For example, as shown in FIG. 3, it may beconsidered that the first power supplying line 107 and the second powersupplying line 112 are connected corresponding to the first USB port104; the first power supplying line 108 and the second power supplyingline 113 are connected corresponding to the second USB port 105; and thefirst power supplying line 109 and the second power supplying line 114are connected corresponding to the third USB port 110 (refer toconnection 2 a and connection 3 a of FIG. 3).

On the basis of the input control signal from the ICH 103 (see FIG. 2),the switching unit 111 may connect the first power supplying line 108corresponding to the second USB port 105 and/or the first powersupplying line 109 corresponding to the third USB port 110 with thesecond power supplying line 112 corresponding to the first USB port 104(refer to connection 2 b and/or connection 3 b of FIG. 3). In this case,the switching unit 111 may disconnect the first power supplying line 108from the second power supplying line 113 and/or the first powersupplying line 109 from the second power supplying line 114. Thus, theelectric power supplied via the first power supplying line 108 and/orthe first power supplying line 109 may be supplied to the externaldevice 201 connected to the first USB port 104 through the second powersupplying line 112. As compared with one first power supplying line 107,one or more first power supplying lines 107, 108 and 109 can supplyrelatively high electric power (i.e., high intensity of current) to theexternal device 201, thereby supplying sufficient electric power to theexternal device 201 that needs the high current or high power.

FIG. 4 illustrates a configuration of the switching unit 111 of FIGS. 2and 3. The switching unit 111 may be achieved in the form of a singleintegrated chip (IC). As shown, the switching unit 111 includes aplurality of switching elements 115 and 116 (refer to FIG. 4) and aswitching driver 117. In this embodiment, the first power supplyinglines 107, 108 and 109 and the second power supplying lines 112, 113 and114 are one to one connected, respectively.

Each of the switching elements 115 and 116 is provided in a pair ofpower supplying lines among the first power supplying lines 107, 108 and109 or the second power supplying lines 112, 113 and 114, and controlsthe connection there between. That is, the plurality of switchingelements 115 and 116 have drains D1 and D2 and source S1 and S2connected to the pair of power supplying lines concerned, respectively.For convenience, the plurality of switching elements 115 and 116 areillustrated only corresponding to the first power supplying lines 107,108 and 109 and the second power supplying lines 112, 113 and 114. Whilenot limited thereto, the switching element 115 has the ground G1connected to the switching driver 117, the drain D1 connected to thefirst power supplying line 107, and the source S1 connected to the firstpower supplying line 108. The switching element 116 has the ground G2connected to the switching driver 117, the drain D2 connected to thefirst power supplying line 107, and the source S2 connected to the firstpower supplying line 109. The switching driver 117 controls voltagesapplied to gates G1 and G2 of the plurality of switching elements 115and 116, thereby driving the plurality of switching elements 115 and 116so as to selectively connect the power supplying lines 108, 109 to thesecond power supplying line 112. While not required in all aspects, likeswitching elements can connect other second power supplying lines to thefirst power supplying lines.

According to another embodiment of the present invention, the switchingunit 111 may include at least one switching element (not shown) providedbetween the first power supplying lines 107, 108 and 109 and thecorresponding second power supplying lines 112, 113 and 114, and theswitching driver 117 may drive the switching element. Thus, the firstpower supplying lines 107, 108 and 109 and the corresponding secondpower supplying lines 112, 113 and 114 may be disconnected.

Below, the control signal input to the switching unit 111 will bedescribed in more detail. In the embodiment as shown in FIG. 2, thecontrol signal is generated by the CPU 101, the MCH 102 and the ICH 103.The ICH 103, which is an input/output controller, generates and outputsthe control signal corresponding to a command of the CPU 101. The CPU101, which is a program executer, executes a computer program andcontrols the ICH 103 to generate a corresponding control signal.

The computer program and software executed by the CPU 101 is stored in acomputer readable medium such as nonvolatile memory (not shown) such asa hard disk drive, and all or some computer programs stored in a readonly memory (ROM) are temporarily loaded to a volatile memory such as arandom access memory (RAM) so as to be read by the CPU 101. The computerprogram loaded to the volatile memory may be read by the MCH 102. Thecomputer program executed by the CPU 101 includes a basic input/outputsystem (BIOS), an operating system such as Windows (registeredtrademark), and application programs.

As described above, the combination of the CPU 101, the MCH 102, the ICH103, the nonvolatile memory, the volatile memory, and the computerprogram to be executed by the CPU 101 may be employed as an example of acontroller according an embodiment of the present invention.Hereinafter, these configurations will refer to the “controller 101, 102and 103”.

In this embodiment, if the external devices 201, 202 and 203 mounted tothe USB ports 104, 105 and 110 draw insufficient electric powertherefrom, the controller 101, 102 and 103 generates the control signalso that two or more power supplying lines among the first powersupplying lines 107, 108 and 109 are connected to one of the USB ports104, 105 and 110 to which the external devices 201, 202 and 203 aremounted.

For example, if the external device 201 is connected to the first USBport 104 among the USB ports 104, 105 and 110 and is lacking in theelectric power, the first power supplying line 108 and/or 109corresponding to the second USB port 105 and/or the third USB port 110may be additionally connected to the second power supplying line 112corresponding to the first USB port 104 (refer to 2 b and/or 3 b of FIG.3). As such, the controller 101,102,103 selectively connects pluralfirst power supplying lines 107, 108, 109 to one of the second powerline 112, 113, 114 of one of the USB ports 104,105,106.

In this embodiment, the controller 101, 102 and 103 may determinewhether the external device 201, 202 and 203 draws electric powersufficiently or insufficiently on the basis of registered information ofthe external device 201, 202 and 203, managed by the operating system ofthe computer system 100.

For example, if the operating system is WINDOWS, whether the externaldevice 201, 202 and 203 draws electric power sufficiently orinsufficiently is determined depending on information about the externaldevice 201, 202 and 203 registered in “Device Manager”. In more detail,when the first external device 201 is mounted to the first USB port 104,it is sensed by Plug-and-Play that the first external device 201 isconnected to the first USB port 104 and it is checked whether there isinformation about the first external device 201 registered in “DeviceManager”. If there is information about the first external device 201registered in “Device Manager”, it is determined that the first externaldevice 201 draws the electric power sufficiently since the firstexternal device 201 is newly connected and draws enough power to berecognized by the computer system 100 as usable by the operating system.If there is no information about the first external device 201registered in “Device Manager”, it is determined that the first externaldevice 201 draws the electric power insufficiently since the firstexternal device 201 is newly connected but does not draw enough power tobe recognized by the computer system 100 as usable by the operatingsystem.

By way of example, whether the external device 201, 202 and 203 islacking in the electric power may be determined at the moment when theexternal device 201, 202 and 203 is mounted to the USB port 104, 105 and110. However, it is understood that this determination can be otherwiseinput, such as by the first external device 201 sending power statusinformation to the operating system after mounting the first externaldevice 201 indicates that, during usage, insufficient power is beingdrawn for certain functions or within a predetermined time aftermounting, such that the detection need not be at the moment the externaldevice 201, 202, 203 is mounted in all aspects of the invention.

When it is determined that there is insufficient power for the mountedfirst external device 201, the controller 101, 102 and 103 may selectthe first power supplying lines 108 and/or 109 corresponding to the idleUSB ports 105 and/or 110, to which the external devices 202 and/or 203are not mounted, among the first power supplying lines 107, 108 and 109as the first power supplying lines 108,109 to be connected to the secondpower supplying line 112 in addition to the first power supplying line107.

If the first power supplying lines 108 and/or 109 corresponding to theidle USB ports 105 and/or 110, to which the external devices 202 and/or203 are not mounted, are not one, the controller 101, 102 and 103 maycontrol the first power supplying lines 108 and 109 to be additionallyconnected to the second power supplying line 112 one by one. In otherwords, the electric power is gradually increased until the firstexternal device 201 draws the electric power sufficiently from the firstUSB port 104.

If there is no first power supplying line to be connected to the secondpower supplying line under the condition that a mounted one among theexternal device 201, 202 and 203 is lacking in the electric power (e.g.,if all USB ports 104, 105 and 110 are occupied with the external devices201, 202 and 203) the controller 101, 102 and 103 may give a user amessage of asking him/her to remove at least other one except the firstexternal device 201 among the external devices 201, 202 and 203. To thisend, the computer system 100 may include a display unit (not shown) todisplay such a message. However, it is understood that the firstsupplying lines can be chosen from USB ports connected to lower priorityexternal devices or external devices which can be idled.

Meanwhile, if the first external device 201 is removed from the firstUSB port 104 after additionally connecting the first power supplyinglines 108 and/or 109 (i.e., if the use of the first USB port 104concerned is terminated) the controller 101, 102 and 103 may control theswitching device 111 to release the additional connection of the firstpower supplying lines 108 and/or 109 so as to reconnect the USB ports105,110 to their corresponding power supplying lines 108,109.

Below, the operations of the controller 101, 102 and 103 will bedescribed in detail with reference to FIG. 5. FIG. 5 is a flowchart foroperation of the controller 101,102,103 shown in FIG. 2. The presentembodiment is premised on the assumption that the first external device201 needing the high current or power is connected to the first USB port104.

First, the controller 101, 102 and 103 determines whether the externaldevices 201, 202 and 203 are mounted to the USB ports 104, 105 and 110(S101). If it is determined that the first external device 201 isconnected to the first USB port 104, the controller 101, 102 and 103determines whether the first external device 201 was registered or noton the basis of the registered information of the first external device201, managed by the operating system (S102). Such registrationinformation indicates that the computer system 100 has recognized thefirst external device 201 is mounted on the computer system 100 and isusable by the computer system 100.

If it is determined that at the stage S102 the first external device 201was registered, the controller 101, 102 and 103 determines that thefirst external device 201 draws the electric power sufficiently, andthus operates normally (S108).

On the other hand, if it is determined at the stage S102 that the firstexternal device 201 was not registered (i.e., the first external device201 has not been previously recognized by the computer system 100 eventhough connected to the USB port 104), the controller 101, 102 and 103determines that the first external device 201 is lacking in the electricpower, and then determines whether there are the idle USB ports 105and/or 110 to which the external devices 201, 202 and 203 are notmounted among the USB ports 104, 105 and 110 (S103). As an alternative,it is understood that other mechanisms can be used to determine whethersufficient energy is drawn beyond reliance on registration informationsuch that operation S102 is not limited to the shown example.

If it is determined at the stage S103 that there are the idle USB ports105 and/or 110, the controller 101, 102 and 103 controls the switchingunit 111 to connect the first power supplying line 108 and/or 109corresponding to the idle USB ports 105 and/or 110 with the second powersupplying line 112 corresponding to the first USB port 104 (S104). Then,returning back to the stage S102, the controller 101, 102 and 103determines again whether the first external device 201 was registered.According to results, a stage following the stage S103 or the stage S108is performed.

On the other hand, if it is determined at the stage S103 that there isno idle USB port 105 and/or 110, the controller 101, 102 and 103 maygive a user a message of asking him/her to remove at least other oneexcept the first external device 201 among the external devices 201, 202and 203 (S105). Alternatively, the controller 101,102 and 103 can send arequest to idle or sleep others of the external devices 202,203according to a prioritized order and automatically switch the firstpower supplying lines without a message to a user.

Then, the controller 101, 102 and 103 finally determines whether thesufficient electric power can be supplied to the first external device201 (S106). For example, there may be no idle USB port even thoughpredetermined time elapses after giving the message at the stage S105.If it is determined at the stage S106 that the sufficient electric powercannot be supplied to the first external device 201, the controller 101,102 and 103 notifies a user of the reason (S107). Here, the display unit(not shown) may be used to display the message at the stage S105.

On the other hand, if it is determined at the stage S106 that thesufficient electric power can be supplied to the first external device201, the controller 101, 102 and 103 determines, returning back to thestage S103, whether there are the idle USB ports 105 and/or 110 to whichthe external devices 202 and 203 are not mounted, and performs the stagefollowing the stage S104 or the stage S105 according to results.

The present invention is not limited to the particular specification ofthe ports and the USB ports are described as a representative port inthe foregoing embodiment. Alternatively, the present invention may beapplied to any port to which the external device can be mounted and fromwhich the external device can draw electric power, and the ports neednot be of the same specification and can be mixtures of specifications(e.g., a USB 1.0 port, a USB 2.0 port, an IEEE 1394 port etc.).

Further, as an alternative to the embodiment of FIG. 5, at least onestage may be omitted among the stages S105, S106 and S107, and thestages S105 and S106 may be interchanged with each other. Further, inthe state that the first power supplying lines 108 and/or 109 areadditionally connected, if the first external device 201 is removed fromthe first USB port 104, an operation of releasing the additionalconnection of the first power supplying lines 108 and/or 109 may beperformed instead of the stage S108.

Also, the first power supplying lines 107, 108 and 109 branched from thepower source Vcc and the corresponding second power supplying lines 112,113 and 114 are described exemplarily, but not limited thereto.Alternatively, the present invention may be applied to a power sourceunit capable of independent power supply.

As described above, the present invention provides a computer systemcapable of supplying sufficient electric power to an external apparatusmounted to a port thereof with low costs, and a control method of thesame.

Further, the present invention provides a computer system capable ofsupplying sufficient electric power to an external apparatus mounted toa port thereof with high reliability and convenience, and a controlmethod of the same.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A computer system comprising: a plurality of ports connectable tocorresponding detachable external devices, each of the ports beingselectively connectable to a plurality of power supplying lines branchedfrom a main power supplying line for supplying electric power to one ofthe external devices when connected to a first one of the ports; aswitching unit which controls connections between the plurality of powersupplying lines and the plurality of ports; and a controller whichcontrols the switching unit so that two or more of the power supplyinglines among the plurality of power supplying lines are connected to thefirst port when the one external device is mounted to jointly supply theelectric power to the one external device.
 2. The computer systemaccording to claim 1, wherein the controller determines whether the oneexternal device is lacking in electric power on the basis of whetherregistered information about the one external device is detected afterthe one external device is mounted, the registered information beingmanaged by an operating system of the computer system.
 3. The computersystem according to claim 1, wherein, while a first one of the powersupplying lines is connected to the first port as at least one of thetwo or more power supplying lines connected to the first port, thecontroller selects a second one of the power supplying lines connectedto a second one of the ports, to which the one external device is notmounted, as at least another one of the two or more power supplyinglines connected to the first port.
 4. The computer system of claim 3,wherein the controller disconnects the second one of the power supplyinglines from the second port while the second power supplying line isconnected to the first port in addition to a first power supplying lineto jointly supply the electric power to the one external device.
 5. Thecomputer system according to claim 1, wherein the controller controlsthe switching unit so that a second one of the two or more powersupplying lines is additionally connected to the first port after afirst one of the two or more power supplying lines is connected to thefirst port.
 6. The computer system according to claim 1, wherein, whenanother one of the external devices is connected to a second one of theports, the controller provides a message to a user asking the user toremove the another one external device mounted to the second port. 7.The computer system according to claim 1, wherein the controllerdisconnects at least one of the two or more power supplying lines fromthe first port when the one external device is removed from the firstport.
 8. The computer system according to claim 1, wherein the switchingunit comprises: a plurality of switching elements, each of whichcontrols a corresponding connection between one of the plurality ofpower supplying lines and one of the plurality of ports; and a switchingdriver which drives the plurality of switching elements according to acontrol signal sent from the controller to control the switching unit.9. The computer system according to claim 8, wherein the controllercomprises: an input/output controller which outputs the control signalto the switching driver; and a program executer which executes acomputer program so that the input/output controller outputs the controlsignal.
 10. The computer system of claim 1, wherein each of ports isconnected to a corresponding one of the power supplying lines and isselectively disconnected from the corresponding power supplying linesaccording to the control of the switching unit.
 11. A method ofcontrolling a computer system, comprising: selecting a first port amonga plurality of ports to which one external device is mounted, the firstport being connectable to a plurality of power supplying lines branchedfrom a main power supplying line for supplying electric power to the oneexternal device and each of the ports being connectable to correspondingexternal devices; and connecting two or more power supplying lines amongthe plurality of power supplying lines to the first port, to which oneof the at least one external device is mounted.
 12. The method accordingto claim 11, wherein the selecting of the first port comprisesdetermining whether the at least one external device is lacking inelectric power on the basis of registered information about the externaldevice, managed by an operating system of the computer system.
 13. Themethod according to claim 11, further comprising, while a first one ofthe power supplying lines is connected to the first port as at least oneof the two or more power supplying lines connected to the first port,selecting a second one of power supplying lines connected to a secondport, to which the at least one external device is not mounted, amongthe plurality of power supplying lines, as at least one of the two ormore power supplying lines to be connected to the first port.
 14. Themethod according to claim 11, wherein the connecting of the two or morepower supplying lines comprises additionally connecting the two or morepower supplying lines to the first port at least one by one.
 15. Themethod according to claim 11, further comprising giving a user a messageasking the user to remove the at least one other external device mountedto other ports among the plurality of ports than the first port.
 16. Themethod according to claim 11, further comprising disconnecting at leastone of the two or more power supplying lines and the first port when theat least one external device is removed from the first port.
 17. Acomputer system comprising: a plurality of ports connectable tocorresponding detachable external devices, each of the ports beingselectively connectable to a plurality of power sources for supplyingelectric power to one of the plurality of external devices whenconnected to a first one of the ports; a switching unit for controllingconnections between the plurality of power sources and the plurality ofports; and a controller for controlling the switching unit to connecttwo or more power sources among the plurality of power sources connectedto the first port, when the one external device is mounted, among theplurality of ports when the controller determines the one externaldevice is lacking in the electric power.
 18. The computer systemaccording to claim 17, wherein the controller determines whether the atleast one external device is lacking in electric power on the basis ofregistered information about the at least one external device, managedby an operating system of the computer system.
 19. A method ofcontrolling a computer system, comprising: selecting a first port amonga plurality of ports to which at least one external device is mounted,each of the ports being selectively connectable to a plurality of powersources for supplying electric power to the at least one external deviceand each of the ports being connectable to corresponding externaldevices; and connecting two or more power sources among the plurality ofpower sources to the first port, to which one of the at least oneexternal device is mounted, among the plurality of ports.
 20. The methodaccording to claim 19, wherein the selecting of the first port comprisesdetermining whether the at least one external device is lacking inelectric power on the basis of registered information about the at leastone external device, managed by an operating system of the computersystem.
 21. A computer system comprising: an interface through which acontrol signal is sent to a switching unit which controls connectionsbetween a plurality of power sources and a plurality of ports; and acontroller which detects when an external device connects to one of theports and receives power from one of the power sources through the oneport, and sends the control signal through the interface to control theswitching unit to selectively connect the power sources to the one portto change a number of power sources connected to the one port in orderto provide sufficient power to the external device.
 22. The computersystem of claim 21, wherein the controller further detects when the oneport does not provide sufficient power to the external device using lessthan all of the plurality of power sources, and sends the control signalthrough the interface to control the switching unit to connect at leastone additional power source among the plurality of power sources to theone port to increase the number of power sources connected to the oneport in order to provide sufficient power to the external device. 23.The computer system of claim 22, wherein the controller detects when theone port does not provide sufficient power when an operating system ofthe computer system does not detect the external device in a DeviceManager.
 24. The computer system of claim 22, wherein the controllerfurther sends the control signal to the switching unit to furtherdisconnect the at least one additional power source from another one ofthe plurality ports to which the one additional power source waspreviously connected.
 25. The computer system of claim 24, wherein thecontroller further detects when the external device is disconnected fromthe one port, and sends another control signal through the interface tothe switching unit to disconnect the at least one additional powersource from the one port and reconnect the at least one additional powersource to the another port.
 26. The computer system of claim 22, whereinthe controller further detects when the external device is disconnectedfrom the one port, and sends another control signal through theinterface to the switching unit to disconnect the at least oneadditional power source from the one port.
 27. The computer system ofclaim 22, wherein the controller further selects as the additional powersource one of the power sources which is not providing power to any ofthe ports prior to being connected to the one port.
 28. The computersystem of claim 27, wherein the controller, prior to selecting theadditional power source, detects that the additional power source isproviding power to another one of the ports to power another externaldevice, sends a request through the interface to discontinue providingthe power to the another external device through the another one of theports, and when the additional power source is no longer providing thepower to the another external device in response to the sent request,selects the additional power source.